Fluid control apparatus



Feb. 9, 1965 R. ADAMS ETAL FLUID CONTROL APPARATUS Filed Dec. 22. 1961FIG.

FIG.

/NvE/vro/as, LESTER R. ADAMS BERNARD J GREENBLOTT 5) mmm/5y FIG. 2

United States Patent O 3,16897 FLUD CNTROL APPARATUS Lester E. Aadams,Endweii, and Bernard i. Greenhlott,

Binghamton, NSY., assignors to international lr'iusiness MachinesCorporation, New York, NX., a corporation of New Yori;

Filed Dec. 22, 196i, Ser. No. 161,709 7 Claims. (Cl. 13T-$1.5)

This invention relates generally to fluid switches and more particularlyto fluid switches controlled by electrical discharge.

Pneumatic and hydraulic switches have been used generally for dynamiccontrol systems to achieve accurate, reliable and easy positioning ofmechanical components. More recently these switches have found increasedutility as computer elements where they are used to direct fluid toselected transmission channels. In turn, the presence of fluid ow orpressure in a particular channel or channels is used to represent data,usually in binary code. However, in many computer applications the slowspeed with which the tlow of pressurized iiuid is transferred from onechannel to another is a serious drawback preventing the production ofshort, sharp pressure pulses.

When the usual mechanical switching devices wege employed. their movablecontrol vanes, diaphragms or pistons and linkages seriously hamperedhigh speed switching because of inertia, friction and wear. As a result,iluid switches were developed which eliminated all movable mechanicalcomponents. Instead, a fluid stream to be controlled, herein called thepower stream, was guided by directing the ilow of one or more low energystreams of identical iiuid known as control streams, usuallytransversely against the power stream. This method of momentuminterchange permitted the use of small, low pressure streams to directthe high energy power stream simply with improved efficiency. Y

A refinement added to this switching action was that of causing thedeilected power stream to lock onto the wall of a particular channel andremain there even though the deflecting control stream was discontinued.One manner of accomplishing lock on was to provide evacuated ports alongthe channel walls to remove decelerated boundary particles beforeseparation occurred, and so maintain smooth flow. Lock on wasaccomplished another way by providing a cavity or set back in thechannel wall which produced an advantageous pressure gradienttransversely of the power stream. Although this reiinement permitted theuse of control stream pulses instead of continuous streams, noimprovement resulted in the switching speed.

There still existed the necessity for a signilicant improvement in theswitching speed of the uid switches. This need was especially evident incomputer applications where the -liuid used was predominately a gas,usually air. Although the control streams were used, pressure pulses hadto be produced and the easy compressability of the gas prevented therapid generation of control pulses. Furthermore, supply and valveapparatus were required for at least some of the control streams, thoughthe power streams were often employed as control streams in subsequentlyconnected tluid switches. The apparatus for generating control streamswas often bulky and added to the complexity of the entire system.

Another disadvantage of using the conventional contro and power streamswas that of conveniently coupling an electrical system to the fluidsystem. Coupling was usually accomplished with the use of electricallycontrolled valves. Valve-controlled fluid systems were extremely slowwhen compared to electrical systems, and the electrical control datagenerated by the latter' system had to be either produced at a slow rateor temporarily stored while the electrical signals were used to operatethe valves in the fluid system. It was desirable, therefore, to improvethe operation of electro-huid system by decreasing the response time ofthe tluid system to short electrical pulses.

Accordingly, a primary object of this invention is to provide a fluidswitch having increased switching speed.

Another object of this invention is to provide apparatus for directingthe flow of the fluid from one channel to another by the generation ofshock and pressure waves adjacent the uid stream.

Another object of this invention is to provide fluid switching apparatusin which a stream of fluid is switched from one transmission channel toanother by electrical discharge.

A further object of this invention is to provide reliable, compactcontrol apparatus for a fluid switching device.

In accordance with the foregoing objects, the switching of uid powerstreams is accomplished by providing electrical discharge means adjacentthe directed stream issuing from a nozzle means. The discharge means arecapable of being controlled selectively to discharge and produce aspark. The sudden high energy discharge produces momentary shock andpressure waves to divert the power stream in a manner similar to controlstreams but with increased speed.

This invention is advantageously adaptable for use with boundary layerswitching devices having the lock on feature, or for use with themomentum interchange type of switch when only temporary deflection ofthe power stream is necessary. Thus, when the invention is used inconjunction with a suitable type of lluid switch, sharp pressure pulsesof various durations may be produced in a transmission channel.

The foregoing and other objects, features and advantages of theinvention will be apparent from the following and more particulardescription of preferred embodiments of the invention, as illustrated inthe accompanying drawings.

In the drawings:

FIG. l is a combined perspective view of a iluid switch and electricalschematic in accordance with the invention;

FIG. 2 is a plan view of another embodiment of a fluid switchincorporating the invention;

FIG. 3 is a sectional View of the uid switch shown in FIG. 2 and takenalong the line 3 3.

Referring to FIG. 1 there is shown a iluid switch generally designatedas 10. The switch includes a nozzle 1l continuously supplied withpressurized fluid, either gas or liquid such as air or water, fromsource 12 through suitable connections. The nozzle forms and directs apower stream of fluid adjacent the surface of wail or airfoil 13 towardthe target or receiving oriiice 14 of a transmission channel 15. Theairfoil surface may be either at or curved and is placed adjacent thestream to utilize the uid boundary layer adhesion to more accuratelydirect the stream to transmission channel 15. The airfoil is formed witha groove 16 therein located transversely to the stream ilow and inwhichis positioned a pair of spaced electrodes 17 and 18 suitablymounted in insulating supports 19. The electrodes are placed adjacentthe stream and each connected to opposite polarities of a controlledsource of potential capable of producing a spark between the electrodes.The electrodes are preferably mounted in a depression so that the fluidstream does not flow directly between them resulting in excessivevoltage requirements to produce a spark.

There are several circuits well known in the art which may beselectively controlled to produce a spark between two electrodes. Anexemplary circuit is shown connected to electrodes 17 and 1S. In thiscircuit each electrode 17 and 1S is connected to one end of a secondarywinding 20 Aof a spark coil 21. The primary winding 22 of the coil hasone end thereof connected to a negative source 'of potential at terminal23 and the other end thereof connected to the collector electrode 24 ofa transistor 25. The transistor emitter is connected to ground and thebase of the transistor is normally biased to cut-off through a pair ofresistors 26 which are, in turn, connected to a source of positivepotential at terminal 27. In operation, a negative electrical pulse isapplied at a terminal 28 between the two resistors and is of sucientmagnitude toV for ward bias transistor causing conduction therein, whichsupplies electrical current to primary winding 22 of the coil, andinduces a high voltage in secondary winding 20 to produce a sparkbetween electrodes 17 and 18. A reversely biased diode 29 `is connectedbetween transistor collector 24 and terminal 23 to protect thetransistor from the effects of counter EMF. when tran sistor conductionterminates at the end of the control signal at terminal 2S.

Displaced upwardly from channel 15 there may be mounted a secondtransmission channel 3i) having a receiving orifice 31. Channels 15 and30' may be similarly equipped at their exhaust ends with indicatingdevices such as dapper valves 32 as illustrated, pistons, diaphragme orthe like. The channels may also extend directly to to other fluidactuated devices which function in accordance with the presence orabsence of fluid flow in the transmission channel. Channel may, ofcourse, be entirely omitted.

In operation, fluid which is either gas or liquid from nozzle 11 Howsacross airfoil 13 and into orice 14 of channel 15 to open its flappervalve 32. When the flapper valve is to be closed, for instance, tooperate electrical contacts, or a fluid pressure pulse is to be producedin channel 30, a momentary electrical spark is produced across the gapbetween electrodes 1'7 and 12S. This spark creates shock and pressurewaves adjacent the power stream which diverts the power stream upwardlyto flow into channel 30 producing a pulse at its apper valve. As thepressure wave terminates, the power stream returns to airfoil 13 andflows again into channel 15. Thus there may be produced a sharp pressurepulse in either channel 15 or 30.

In FIGS. 2 and 3 there is shown a modification of the fluid switchdescribed above. The modified switch includes face plate 35 and backblate 36 between which are located airfoils 37 and 38, and blade 39. Theairfoils and blade are suitably secured between the face and back platesto `form a fluid-tight channel 40 having two diverging output channels41 and 42 branching therefrom. Blade 39 is located so as to bisectchannel 40. Each branch channel has a spur channel connected theretowith spur channel 43 connected with channel 41 and spur channel 44connecting with channel d2. Each spur channel may communicate withsubsequent uid switches or be equipped with indicating devices such aspistons, diaphragms or apper valves 45 and 46, respectively illustrated.Channels 41 and 42 proper may exhaust into any suitable fluid sink, e.g.the atmosphere.

Each airfoil 37 and 38 has formed therein one or more slots 47 connectedto a continuous source of vacuum 48. Also formed in the wall of eachairfoil is a recess 5G into which extends a pair 51 or 52 of spacedelectrodes supported in plates 35 and 36. For example, electrodes 53 and54 of pair 51 extend slightly into the recess of airfoil 37 as seen inFIG. 3. The recesses are provided to permit positioning each electrodepair out of the direct ow of the power stream in channel 40. Each pairof electrodes is suitably connected to an independent spark controlcircuit similar to that shown in FIG. l, which may be selectivelyoperated to produce a spark between the electrodes. Plates 35 and 36,airfoils 37 and 38 and blade 39 are made of any suitable material whichcan be conveniently formed. However, a dielectric material is ret quiredadjacent the electrodes to prevent shorting out the electrical spark.

In operation the switch is supplied with pressurized fluid from pump 55suitably connected to the switch to direct fluid between airfoils 37 and38 to `form a power stream in channel liti. Initially, the uid will bedivided between divergent channels 41 and 42 and will exhaust into theatmosphere with slight bleed off into channels 43 and 44. However, oneor the other of electrode pairs 51 or 52 is energized from a suitablecircuit to produce a spark and divert the power streamfrom its airfoil.For instance, electrode pair 51 may be energized causing substantiallythe entire power stream to be diverted into channel 42. When diversionoccurs, the static pressure from sink port 56 appears at blade tip 33aand cooperates with the vacuum at slot 47 in airfoil 33 so that thediverted stream remains in channel 42. Increased tiow occurs also inchannel 44 to operate apper valve 45. Similarly, when the power streamin channel 4? is to be diverted to channel 41, electrode pair 52 isenergized which creates a shock and pressure wave on the right side 'ofthe stream forcing the stream to be diverted to the left as viewed inFIG. 2 to thereby enter channel 41. The stream, when so diverted, willremain in channel 41 because of static pressure from sink port 57 andthe vacuum at slot 47 in airfoil 37 which combined to produce a pressuregradient transversely of the power stream. Thus there lis provided afluid switch capable of responding substantially instantaneously to anelectrical signal.

While the invention has been particularly shown and described withreference to preferred embodiments thereof it will be understood bythose skilled in the ar-t that changes in form and detail may be madetherein without departing yfrom the spirit and scope of the invention.

What is claimed is: l. Fluid control apparatus to which pressurized uidis supplied, comprising, in combination;

(a) nozzle means for directing said huid as a stream toward a targetarea; and (b) electrical spark-producing means adjacent said stream fordiverting said stream from said target area. 2. Fluid control apparatusto which pressurized fluid is supplied, comprising:

(a) an output channel for said fluid; (b) means connected to saidpressurized uid for directing said fluid into said channel; and (c)means for producing an electrical spark adjacent said directed fluid todivert said fluid from said channel. 3. Fluid control apparatus to whichpressurized uid is supplied, comprising:

(a) an output channel for said fluid; (b) means connected to saidpressurized fluid for directing said uid toward said channel; and (c)means selectively operable for producing an electrical spark adjacentsaid directed uid and diverting l said uid from said channel.

4. A control device for pressurized fluid comprising, in combination:

(a) a pair of transmission channels for said fluid; (b) a nozzle fordirecting said tluid toward one of said channels; and (c) electricalsparking means adjacent said directed iluid for diverting said fluidinto said 'other channel.

5. A control devicefor pressurized fluid comprising, in combination:

(a) a pair of transmission channels `for said uid;

(b) means for directing said iiuid into one of said channels;

(c) wall means interconnecting said directing means and said one channelto maintain said uid flowing from said directing means to said onechannel; and

5 5 (d) electrical means producing a spark adjacent said (b) Wallsdefining a chamber communicating with said directed fluid forredirecting said fluid into the other channels and having a plurality ofrecesses therein, of said channels. each said recess corresponding toone of said chan- 6. Fluid control apparatus to Which pressurized fluidis nels; supplied, comprising: 5 (c) nozzle means for directing saidfluid in said cham- (a) Walls deiining a chamber; ber adjacent one ofsaid recesses and into a cor- (b) a pair of output channelscommunicating with said responding channel; and

chamber; (d) electrical spark-producing means in each said (c) nozzlemeans communicating with said chamber for recess selectively operablefor diverting said directed directing said pressurized uid into saidchamber; and 10 ud ff0l11 S Said Channel and IeCeSS t0 another (d)electrical spark-producing means selectively oper- 0f sind Channels'lnfltsdwertmg sald dlrected uld lnto one of said Reeens Cited in the meof this patent 7. A control device for fluid supplied thereto underUNTED STATES PATENTS pressure, comprising, in combination: l5 3,001,539Hurvitz Sept. 26, 1961 (a) a plurality of transmission channels for saidfluid; 3,071,154 Cargill i Jan. 1, 1963

1. FLUID CONTROL APPARATUS TO WHICH PRESSURIZED FLUID IS SUPPLIED,COMPRISING, IN COMBINATION: (A) NOZZLE MEANS FOR DIRECTION SAID FLUID ASA STREAM TOWARD A TARGET AREA; AND (B) ELECTRICAL SPARK-PRODUCING MEANSADJACENT SAID STREAM FOR DIVERTING SAID STREAM FROM SAID TARGET AREA.